The concurrent growth of plants and chemical purification of wastewater used as a hydroponic unit.

: In this study the seedling of a variety of plants were successfully grown hydroponically on raw wastewater obtained from one of the main sewer outfalls in Beirut. In the first phase, a series of experiments was run on a batch system in glass or plastic containers provided with aeration facilities. A continuous-flow system with recirculation was adopted in the second phase. Iron supplementation was applied in all cases to compensate for its deficiency in the raw wastewater used. The immediate and ultimate objectives of the project were threefold: (a) to demonstrate the feasibility of utilizing as a hydroponic medium untreated municipal wastewater having relatively high mean values for BOD and mineral content; (b) to achieve the growth of useful plants on such readily available hydroponic media, thereby saving on fertilizers and scarce water resources; and (c) reclamation of the wastewater through biological purification leading to the gradual depletion of the nutritive constituents. Experimental conditions are described, and the data presented leads to the conclusion that the system is practicable on a laboratory scale. It has great potential for trial on a pilot scale prior to field applications in developing countries suffering from water shortage and hard currency expended on imported fertilizers and wastewater purification facilities.